I have not had my cactus for long so I am not really sure how worrying this is, but it does look unpleasant and I am sure it can't be a good thing. The leaves on my Madagascar Palm keep turning black, they don't feel dry they just seem to turn black from the ends of the leaves. I thought at first that I was over watering it, but a week later without more water and the same thing is still happening. I had to pull off another 3 leaves this morning.Does anybody have any suggestions on how to fix this, does it just need more time without water?

Soon someone will post here and tell you "that is NOT cacti" And a pic or two couldn't hurt. But if it's just throwing leaves away it could be normal. Sometimes it does that ower winter. So... Post some pics.

The effects of overwatering, especially on succulents, can be seen for some time after you correct the issue. In fact the soil may not have even dried out enough yet, particularly if the plant happens to be overpotted. Unless you are in a very warm climate you probably would only need to water once per week at most, and two weeks might be better.

Can you tell us your growing conditions (indoors or outdoors? if outside where do you live?) and maybe even take a picture of the plant and pot?

It may just be normal leaf loss. I water them frequently when the top is bright green & actively growing, then much-much less when dormant. I was frying one in a greenhouse for a while and the leaf tips turned black, then after I put it in a cooler spot with less sunshine it really took off and is growing like crazy.